The Straits Times reports that the distributors, which supply more than 90 per cent of fresh chicken products in the country, could face fines if found to have infringed anti-competition rules.

Today (21 December), the Competition Commission of Singapore issued a Supplementary Proposed Infringement Decision against the suppliers, after "new evidence involving allegations of fact and admissions" was brought to its attention.

The suppliers have six weeks to address the new evidence, before the commission makes its final decision.

When asked, the commission said it could not give details of the new evidence as investigations are ongoing.

The firms have applied for lenient treatment after the new evidence turned up, said the commission. Under the commission’s Leniency Programme, firms that give the commission information on their cartel activities are afforded lenient treatment, where they can be granted total immunity or have their fines reduced completely or by half.

Investigations into the fresh chicken distributors started in March 2014. The commission found that the parties met to discuss prices from 2007 to 2014 and "expressly coordinated" the price increases of products. This was aimed at distorting the prices of certain fresh chicken products in Singapore, it added.

The suppliers also agreed not to compete for one another's customers during these discussions, which restricted the choices available to customers.

"As such, the implementation of the agreed price increases impacted a significantly large number of distributors and customers, including supermarkets, restaurants, hotels, wet market stalls and hawker stalls, and ultimately consumers of these chicken products," said the commission.

In March 2016, a Proposed Infringement Decision was imposed on the 13 suppliers. The commission said new evidence came to light when the parties made written and oral representations to the initial proposed decision issued.

The 13 suppliers are: Gold Chic Poultry Supply, Hua Kun Food Industry, Hock Chuan Heng Farm and its sole proprietor Hy-fresh Industries (S), Kee Song Food Corporation (formerly Kee Song Brothers Poultry Industries), Lee Say Poultry Industrial and its sole-proprietor Lee Say Group, Hup Heng Poultry Industries, KSB Distribution, Prestige Fortune (S), Ng Ai Muslim Poultry Industries, Sinmah Poultry Processing (S), Toh Thye San Farm, Tong Huat Poultry Processing Factory and Ban Hong Poultry.

The commission has the power to fine companies up to 10 per cent of the turnover of their business in Singapore for each year of infringement, up to a maximum of three years.

The total turnover of the 13 firms amounts to about $500 million annually, The Straits Times reported last year.